Rotary pumps



1964 E. WOYDT 3,152,556

ROTARY PUMPS 5 Sheets-Sheet 1 Filed Dec. 10. 1962 B E 3-49 J A 20 gl 2'7 20 t? 30 i E I 7 26 sq- INVENTOR.

E. WOYDT Oct. 13, 1964 ROTARY PUMPS 5 Sheets-Sheet 2 Filed Dec. 10, 1962 E. WOYDT ROTARY PUMPS 5 Sheets-Sheet 3 Filed Dec. 10, 1962 Oct. 13, 1964 E. WOYDT 3,152,556

ROTARY PUMPS Filed Dec. 10: 1962 5 sheets-sheet 5 fliZ. 25

IN V EN TOR.

United States Patent 3,152,556 ROTARY PUB ES Eduard Woydt, Wagenhurgstrasse 5, Stuttgart, Germany Filed Dec. 10, 1962, Ser. No. 243,410 Claims priority, applicatien Germany Dec. 14, 1961 7 Claims. ((31. 103-174) This invention relates to pumps of the type more commonly referred to as rotary pumps, and in which a plurality of rotating cylinders are provided with pistons which reciprocate therein as a result of the rotation of the cylinders.

Heretofore numerous pumps of this general type have been provided and utilized, but many of these have certain disadvantages such as the necessity for operating the same at a relatively low speed in order to eliminate problems arising from centrifugal force, and furthermore, the capacity of such pumps was materially limited by the fact that each piston only makes one reciprocation per revolution of the cylinder. Furthermore, prior art pumps of this type were limited as to the maximum discharge pressure possible, since frictional problems increase with an increase in pressure, and when operating at relatively high pressure, such pumps tend to overheat.

It is accordingly an object of the invention to provide a pump of relatively high capacity and high pressure, in which problems occasioned by centrifugal force and excess friction losses have been eliminated.

A further object of the invention is the provision of a pump having a plurality of rotatable cylinders with a piston reciprocable in each cylinder, and in which each piston makes several reciprocations during one revolution of the body carrying the cylinders, thereby materially increasing the capacity of the pump when compared to a pump in which the piston only makes one reciprocation per revolution.

A still further object of the invention is the provision of a pump of the type having a plurality of cylinders carried by a rotating body with a piston reciprocable in each cylinder, and which by reason of the particular design of the pump permits the provision of a relatively large number of cylinders in a pump of relatively small dimensions.

Another object of the invention is the provision of a pump including a plurality of cylinders carried by a rotating body, and with a piston reciprocable in each cylinder and in which a plurality of rollers fixed in a housing serve to successively reciprocate the pistons upon rotation of the body, it being noted that the only mass subjected to centrifugal force is the piston, and consequently problems arising from centrifugal force resulting from high speed operations are eliminated.

A further object of the invention is the provision of a pump of the type having a plurality of cylinders carried by a rotating body, and a piston reciprocable in each cylinder, and in which manually adjustable means is provided for infinitely varying the pump output from zero to maximum.

A still further object of the invention is the provision of a pump of the type having a plurality of cylinders carried by a rotating body, and a piston reciprocable in each cylinder, and in which said pump may be conveniently converted to operate as a motor with only minor modifification thereof.

Further objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side elevational view, with parts broken away and in section for greater clarity, and showing a pump constructed in accordance with this invention;

FIG. 1A a fragmentary sectional view showing a modification;

FIG. 2 a fragmentary sectional view taken substantially on the line IIII of FIG. 1;

FIG. 3A a fragmentary sectional view taken substantially on the line AA of FIG. 1;

FIG. 3B a fragmentary sectional view taken substantially on the line BB of FIG. 1;

FIG. 3C a fragmentary sectional view taken substantially on the line CC of FIG. 1;

FIG. 3D a fragmentary sectional view taken substan tially on the line D-D of FIG. 1;

FIG. 4, a fragmentary elevational View showing the relationship between a piston, an operating rocker arm, and the roller engaged by the rocker arm;

FIG. 5 a diagrammatic view showing the operation of various portions of the pump to provide a visual comparison between such operations;

FIG. 6 a front elevational view of a pump constructed in accordance with this invention; and,

FIG. 7 an end elevational view of the pump shown in FIG. 6.

With continued reference to the drawing, there is shown a pump constructed in accordance with this invention, and which may Well comprise a housing consisting of a main part 1, a filler plate 2, and an end plate 3. The parts of the housing may be secured together in any suitable manner such as by screw threaded fastenings or the like. A shaft 5 is rotatably mounted in bearings 6 and 7 in the-housing, and the shaft 5 carries an enlarged body 5a disposed within the housing. A plurality of cylinder bores 8 are provided in the body So, and slidably mounted in each cylinder bore 8 is a piston 9. As shown in FIG. 1, the cylinders 8 are disposed at an angle to the axis of rotation of the body 5a, but actually such cylinders may be disposed parallel to the axis or at any angle between parallelism and right angles thereto. Each piston 9 is provided with a washer 11 fixed thereto, and a compression spring 10 is disposed between the washer 11 and the body 5a in order to bias the piston 9 outwardly of the cylinder 8.

Pivotally mounted on the body 5a are a plurality of rocker arms 17, there being one such arm for each such piston 9, and as clearly shown in FIG. 3C, the rocker arms 17 are pivotally mounted on a bracket 15, and the body 5a at the leading end of the rocker arm 17 with respect to the direction of rotation of the body 5, and it will be noted that the rocker arm 17 extends rearwardly with respect to the direction of the rotation of the body 5, and is disposed above and in contact with the outer end of piston 9. As best shown in FIG. 4, each rocker arm 17 is provided with a curved, cam surface 17a on the outer side thereof, the purpose of which will presently appear. It is also apparent from FIG. 30 that each rocker arm 17 is of substantially U-shape, and that the trailing end of each rocker farm is disposed between the legs of the next succeeding rocker arm. This construction operates to reduce the dimensions required to accommodate the various elements of the invention.

A plurality of rollers 18 are rotatably mounted in the housing 1 at angularly spaced intervals, such rollers being rotatably mounted on a pin 18a, and as clearly shown in FIG. 4 the roller 18 engages the curved cam surface 17a of the rocker arm 17 as the body 5a rotates to carry the rocker arm 17 by the roller 18 which is stationary with respect to the body 5a. In this manner, each time a roller 18 engages the cam surface 17a of the rocker arm 17, the rocker arm is depressed to move the piston 9 inwardly of the cylinder 8, thereby providing a pumping stroke.

It will consequently be seen that the number of piston strokes per revolution of the body a is determined by the number of rollers 13 provided, and in the form shown in the drawing five such rollers are provided which results in providing five reciprocations of each piston 9 for each rotation of the body 5a, and since, as shown, there are nine pistons provided, this results in forty-five (45) pump strokes per revolution of the body 5a. In this manner the capacity of the pump is materially increased when compared to pumps of this general type in which each piston only makes one pump stroke during each revolution thereof.

A piston-type control valve 25 is slidably mounted in the body 5n, there being one such valve for each cylinder 8, and it will be noted from an inspection of FIG.l that the cylinder 8 communicates with the bore-receiving valve 25 through a passage 29. A cam ring 24 is fixed in the housing, and a cam follower 29 provided on the piston valve 25 engages the cam ring 24, and operates to reciprocate the piston valve 25 upon rotation of the body 511. An intake fitting 26 is provided on the end plate 3 of the housing, and such fitting 26 communicates through a passage 27, with the bore receiving the control valve 25.

In a similar manner, a discharge fitting 34 is provided on the end plate 3 of the housing, and such discharge fitting 34 communicates through a passage 33 and a passage 30 with the bore receiving the piston valve 25. Disposed in the passage 30 is a check valve 31 which is biased toward the closed position by a compression spring 32, and the check valve 31 operates to close the discharge passage during a suction stroke of the piston 9 in the cylinder 8.

During operation, the body 5a rotates, thereby rotating the cylinders 8 and pistons 9, with the result that the pistons 9 are reciprocated by successive engagement of the rocker arms with the rollers 18, and the movement of the cam follower 25? on the piston valve 25 with respect to the fixed cam 24, operates to control movement of the piston valve 25 to open and close the intake and discharge passages from the cylinder 8 to permit a pumping operation. In certain instances, if desired, the check valve 31 may be omitted, and the operation of each cylinder controlled exclusively by the piston-type valve 25.

Since it is desirable to provide for control of the pump output, there has been provided a plurality of piston-type control valves 19, one for each cylinder 8, and as clearly shown in FIG. 1, the bore containing slide valve 19 also communicates through passage 29 with the cylinder 8, and through passage 28 with the intake fitting 26. A cam 21 is rotatably mounted in the housing and provided on the cam 21 is a gear 22 which meshes with a slidable rack 23, whereby upon reciprocation of the rack 23, the cam 21 will be rotated in the housing. A cam follower Zfia is provided on the slide valve 19, and such cam follower engages the cam ring 21. By appropriate adjustment of the cam ring 21, the slide valve 19 may be so operated as to provide a variable vent from the cylinder 8 to the intake fitting 26, and operates during the pressure stroke of the piston 9 to control the output from each cylinder 8 from zero to a maximum, thereby providing for infinite adjustment of pump output.

FIG. 5 serves to provide a graphical representation of the relative movements of the piston 9, the control valve 25 and the control valve 19 during one cycle of operation provided by a pressure and suction stroke of the piston 9.

The line td-41 represents the pressure stroke of the piston 9 while the line 41-42 represents the suction stroke of the piston 9. The operation of the control valve 25 during the pressure stroke of the piston 9 is shown by the line 43, 44, 45 with the valve 25 being closed at 43, fully open at 44 and closed at 45. For full pump output, the control valve 19 remains closed during the entire pressure stroke of the piston, as shown by the solid line 47-48.

The operation of the control valve 25 during the suction stroke of the piston 9 is shown by the line 45-46, and extending to the vertical line 42-54 during which time the valve 25 remains closed. The operation of the control valve 19 during the suction stroke of the piston 9 is shown by the full line 48, 49, 54 with the valve 19 being closed at 43, fully open at 49 and closed at 54.

For other than maximum output conditions, the cam 21 may be adjusted to provide an infinite number of dilferent relationships between the operation of the piston 9 and movement of the control valve 19, one such condition being shown by the dot-dash line which indicates that the valve 19 is closed at 51, and moves to fully open position 52 during the last half of the pressure stroke of piston 9 and moves to closed position 53 during the first half of the suction stroke of piston 9 and remains closed during the last half of the suction stroke.

Another condition is shown by the dotted line which indicates that the valve 19 is closed at 47 at the start of the pressure stroke of piston 9, moves to fully open position 50 midway of the pressure stroke and moves to closed position 48 at the end of the pressure stroke. This latter condition is for zero output of the pump.

It is also entirely feasible to operate the pump of this invention as a motor, and for this purpose only minor modification is required, such modification being shown in FIG. 1A in which a compression spring 13 engages a cup-shaped member 12 secured to the piston 9, and with the spring 13 operating between an abutment 14 on the body So, and the cup-shaped member 12 the piston 9 is biased inwardly of the cylinder 8, with the result that introduction of fluid pressure to the cylinder 3 operates to force the piston 9 outwardly against the action of compression spring 13. In the use of the pump of this invention as a motor, the control valve 19 and the check valve 31 are omitted.

It will be seen that by the above-described invention there has been provided a relatively simple, yet highly elfective pump which may be adjusted for an infinite variation of the output capacity, and in which friction losses and the effects of centrifugal force are reduced to a minimum.

It will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof, and therefore, the invention is not limited by that which is shown in the drawings and discribed in the specification, but only as indicated in the appended claims.

What is claimed is:

1. A pump comprising a housing, a body mounted for relative rotational movement in said housing, a shaft fixed to said body, said body having a plurality of cylinder bores therein, a piston slidably disposed in each bore, means biasing each piston outwardly of the associated bore, a plurality of rocker arms pivotally mounted on said body, each rocker arm engaging the associated piston at a point remote from the pivot point, a plurality of rollers mounted in said housing and successively engageable with said rocker arms upon relative rotational movement of said body in said housing to move said pistons inwardly of said bores, an intake fitting on said housing, an intake passage in said body communicating with said fitting and each bore, a discharge fitting on said housing, a discharge passage in said body communicating with said discharge fitting and each bore, a check valve in said discharge passage, a plurality of piston-type control valves carried by said body and constructed and arranged to control communication between each bore and intake and discharge passages, a cam ring fixed to said housing and a cam follower on each piston type valve engaging said cam ring to operate said piston type valve upon relative rotational movement of said body in said housing, whereby upon relative rotational movement of said body in said housing said rocker arm will successively engage said rollers to operate said pistons and provide a pumping action, the number of operations of each piston per revolution of said body being equal to the number of rollers provided.

2. A pump as defined in claim 1, in which each rocker arm is of generally U-shape, with each arm disposed between the legs of the next succeeding arm.

3. A pump as defined in claim 1 in which the axes of said bores are disposed at an angle with respect to the axis of rotation of said body.

4. A pump as defined in claim 1, in which each rocker arm is curved to provide a cam surface for engaging said rollers.

5. A pump as defined in claim 1, in which a second piston type valve is provided for controlling communication between each bore and said intake and discharge passages, a second cam ring rotatably mounted in said housing, a cam follower on each of said second piston type valves engaging said second cam ring, and means to move said second cam ring to vary the point of operation of said second piston type valves with respect to the operating point of said first piston type valves and the operation of said pistons to provide for infinite adjustment of pump output.

6. A pump comprising a housing, a body mounted for relative rotational movement in said housing, a shaft fixed to said body, said body having a plurality of cylinder bores therein, a piston slidably disposed in each bore, means biasing each piston outwardly of the associated bore, a plurality of rocker arms pivotally mounted on said body, each rocker arm engaging the associated piston at a point remote from the pivot point, a plurality of rollers mounted in said housing and successively engageable with said rocker arms upon relative rotational movement of said body in said housing to move said pistons inwardly of said bores, an intake fitting on said housing, an intake passage in said body communicating with said fitting and each bore, a discharge fitting on said housing, a discharge passage in said body communicating with said discharge fitting and each bore, a plurality of piston type control valves carried by said body and constructed and arranged to control communication between each bore and said intake and discharge passages, a cam ring fixed to said housing and a cam follower on each piston type valve engaging said cam ring to operate said piston type valve upon relative rotational movement of said body in said housing, whereby upon relative rotational movement of said body in said housing said rocker arms will successively engage said rollers to operate said pistons and provide a pumping action, the number of operations of each piston per revolution of said body being equal to the number of rollers provided.

7. A pump comprising a housing, a body mounted for relative rotational movement in said housing, a shaft fixed to said body, said body having a plurality of cylinder bores therein, a piston slidably disposed in each bore, means biasing each piston outwardly of the associated bore, a plurality of rocker arms pivotally mounted on said body, each rocker and engaging the associated piston at a point remote from the pivot point, a plurality of rollers mounted in said housing and successively engageable with said rocker arms upon relative rotational movement of said body in said housing to move said pistons inwardly of said bores, an intake fitting on said housing, an intake passage in said body communicating with said fitting and each bore, a discharge fitting on said housing, a discharge passage in said body communicating with said discharge fitting and each bore, a plurality of piston type control valves carried by said body and constructed and arranged to control communication between each bore and said intake and discharge passages and means to operate said piston type valves in timed relation to the relative rotational movement of said body in said housing, whereby upon relative rotational movement of said body in said housing said rocker arms will successively engage said rollers to operate said pistons and provide a pumping action, the number of operations of each piston per revolution of said body being equal to the number of rollers provided.

References Cited in the file of this patent UNITED STATES PATENTS 385,226 Barden June 26, 1888 1,274,955 Sundh Aug. 6, 1918 1,964,245 Benedek et al June 26, 1934 2,662,374 Woydt Dec. 15, 1953 2,929,334 Panhard Mar. 22, 1960 FOREIGN PATENTS 832,853 Germany Feb. 28, 1952 

1. A PUMP COMPRISING A HOUSING, A BODY MOUNTED FOR RELATIVE ROTATIONAL MOVEMENT IN SAID HOUSING, A SHAFT FIXED TO SAID BODY, SAID BODY HAVING A PLURALITY OF CYLINDER BORES THEREIN, A PISTON SLIDABLY DISPOSED IN EACH BORE, MEANS BIASING EACH PISTON OUTWARDLY OF THE ASSOCIATED BORE, A PLURALITY OF ROCKER ARMS PIVOTALLY MOUNTED ON SAID BODY, EACH ROCKER ARM ENGAGING THE ASSOCIATED PISTON AT A POINT REMOTE FROM THE PIVOT POINT, A PLURALITY OF ROLLERS MOUNTED IN SAID HOUSING AND SUCCESSIVELY ENGAGEABLE WITH SAID ROCKER ARMS UPON RELATIVE ROTATIONAL MOVEMENT OF SAID BODY IN SAID HOUSING TO MOVE SAID PISTONS INWARDLY OF SAID BORES, AN INTAKE FITTING ON SAID HOUSING, AN INTAKE PASSAGE IN SAID BODY COMMUNICATING WITH SAID FITTING AND EACH BORE, A DISCHARGE FITTING ON SAID HOUSING, A DISCHARGE PASSAGE IN SAID BODY COMMUNICATING WITH SAID DISCHARGE FITTING AND EACH BORE, A CHECK VALVE IN SAID DISCHARGE PASSAGE, A PLURALITY OF PISTON-TYPE CONTROL VALVES CARRIED BY SAID BODY AND CONSTRUCTED AND ARRANGED TO CONTROL COMMUNICATION BETWEEN EACH BORE AND INTAKE AND DISCHARGE PASSAGES, A CAM RING FIXED TO SAID HOUSING AND A CAM FOLLOWER ON EACH PISTON TYPE VALVE ENGAGING SAID CAM RING TO OPERATE SAID PISTON TYPE VALVE UPON RELATIVE ROTATIONAL MOVEMENT OF SAID BODY IN SAID HOUSING, WHEREBY UPON RELATIVE ROTATIONAL MOVEMENT OF SAID BODY IN SAID HOUSING SAID ROCKER ARM WILL SUCCESSIVELY ENGAGE SAID ROLLERS TO OPERATE SAID PISTONS AND PROVIDE A PUMPING ACTION, THE NUMBER OF OPERATIONS OF EACH PISTON PER REVOLUTION OF SAID BODY BEING EQUAL TO THE NUMBER OF ROLLERS PROVIDED. 